The Columbian Exchange was the widespread transfer of plants, animals, diseases, people, and ideas between the Old World (Europe, Asia, and Africa) and the New World (the Americas) following Christopher Columbus's voyages beginning in 1492. It involved the exchange of crops like potatoes, maize, and tomatoes from the Americas to Europe, as well as livestock such as horses, cattle, and pigs from Europe to the Americas. This exchange dramatically reshaped diets, agriculture, environments, societies, and populations on both sides of the Atlantic. It also included the tragic unintentional spread of diseases like smallpox to indigenous American populations, which caused catastrophic population declines. The Columbian Exchange is considered a pivotal event in world history with long-lasting global impact.